Wireless communication system compulsively turning remote terminals into inactive state

• US 6,069,929 A
• Filed: 08/22/1997
• Issued: 05/30/2000
• Est. Priority Date: 04/26/1991
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Sasaki, Norio, Yabe, Toshihiro
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): WEBSTER, BRYAN E
• Application Number:
  US08/916,416
• Time in Patent Office: 1,012 Days
• Field of Search: 375/354, 375/368, 375/369, 375/227, 375/222, 375/316, 455/70, 455/38.3, 455/38.2, 455/205, 455/343, 455/574, 371/5.5, 371/5.3, 371/5.1
• US Class Current: 375/368
• CPC Class Codes: H04W 52/0238 where the received signal is an unwanted signal, e.g. interference or idle signal
• CPC Class Codes: H04W 88/022 Selective call receivers
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A wireless communication system containing at least one transmission apparatus and at least one communication terminal. The transmission apparatus transmits a wireless signal representing a bit sequence containing at least a predetermined number of bit errors, to the communication terminal. The communication terminal receives the wireless signal to regenerate the bit sequence. The communication terminal then examines the bit sequence represented by a received wireless signal to determine whether or not the number of bit errors contained in the bit sequence is equal to or greater than a predetermined number. When it is determined that at least the predetermined number of bit errors are contained in the bit sequence represented by a received wireless signal, the operation of the communication terminal is made inactive. Further, the transmission apparatus may transmit a wireless signal representing a bit sequence containing no pattern coinciding with a predetermined frame synchronization pattern, to the communication terminal. The communication terminal receives the wireless signal to regenerate the bit sequence. The communication terminal then examines the bit sequence represented by a received wireless signal to determine whether or not the bit sequence contains the predetermined frame synchronization pattern. When it is determined that the bit sequence does not contain the predetermined frame synchronization pattern, the operation of the communication terminal is made inactive.

Claims

1. A wireless communication system, comprising:

at least one wireless communication terminal; and

at least one transmission apparatus for transmitting a wireless signal containing a preamble portion and a non-preamble portion, to said at least one wireless communication terminal;

said transmission apparatus comprises turn-off signal transmission means for transmitting, as a part of the non-preamble portion, a turn-off signal representing a bit sequence containing no pattern coinciding with a predetermined frame synchronization pattern;

said at least one wireless communication terminal comprises;

receiving means for receiving a wireless signal as a received wireless signal, and regenerating a bit sequence represented by the non-preamble portion of the received wireless signal,

frame synchronization pattern detection means for trying to detect said predetermined frame synchronization pattern in the bit sequence represented by the non-preamble portion of the received signal, and

sleep mode control means for changing an operation mode of the wireless communication terminal from a working mode to a sleep mode to reduce power consumption of the wireless communication terminal when the frame synchronization pattern detection means fails to detect the frame synchronization pattern in the bit sequence represented by the non-preamble portion of the received signal, in the working mode operation.

2. A wireless communication terminal, comprising:

receiving means for receiving a wireless signal containing a preamble portion and a non-preamble portion, as a received wireless signal, and regenerating a bit sequence represented by the non-preamble portion of the received wireless signal,

frame synchronization pattern detection means for attempting to detect a predetermined frame synchronization pattern in the bit sequence represented by the non-preamble portion of the received wireless signal, and

sleep mode control means for changing an operation mode of the wireless communication terminal from a working mode to a sleep mode to reduce power consumption of the wireless communication terminal when the frame synchronization pattern detection means fails to detect the frame synchronization pattern in the bit sequence represented by the non-preamble portion of the received wireless signal, in the working mode operation.

3. A method of controlling a pager, comprising:

producing a bit sequence that does not contain a frame synchronization pattern;

transmitting a preamble portion followed by a non-preamble portion representing the bit sequence, to the pager; and

changing an operation mode of the pager from a working mode to a sleep mode to reduce power consumption of the pager when a frame synchronization pattern is not detected by the pager in the non-preamble portion.

4. A process for making an operation of an apparatus inactive, by remote control, said process comprising:

transmitting to said apparatus a wireless signal containing a preamble portion and a non-preamble portion, said non-preamble portion representing a bit sequence containing no pattern coinciding with a frame synchronization pattern;

receiving said wireless signal by said apparatus;

trying, in said apparatus, to detect the frame synchronization pattern in the bit sequence represented by the non-preamble portion of the received signal; and

changing the operation mode of the apparatus from a working mode to a sleep mode to reduce power consumption of the apparatus when the frame synchronization pattern detection fails to detect the frame synchronization pattern in the bit sequence represented by the non-preamble portion of the received signal.

5. A wireless communication system, comprising:

a receiving device receiving a wireless signal containing a preamble portion and a non-preamble portion;

a pattern detector determining the presence of a predetermined pattern in the non-preamble portion of said received wireless signal; and

a mode controller changing the operation mode of said receiving device from a first mode to a second mode when said pattern detector fails to determine the presence of said predetermined pattern.

6. A method of remotely changing the operation mode of a receiving device, comprising:

receiving a wireless signal at the receiving device, wherein the wireless signal includes a preamble portion and a non-preamble portion;

determining, at the receiving device, the presence of a predetermined pattern in the non-preamble portion of the wireless signal; and

changing the operation mode of the receiving device from a first mode to a second mode if the determining step fails to detect the predetermined pattern.